Many agricultural formulations contain water-soluble salts. These salts, often alkylamine salts, are generally not as active as their acid equivalents. For example, 2,4-Dichlorophenoxyacetic acid (2,4-D acid) is known to be more herbicidally active than the dimethylamine salt of 2, 4-D. However, 2, 4-D acid is not soluble in water. Solvents used to formulate 2,4-D acid are known to be phytotoxic to plants and enhance herbicide volatility and subsequent drift to non-target areas. In another example, boron is known to be available to plants only in the boric acid form. However, boric acid is only soluble at relatively low concentrations in water, while the Monoethanolamine salt of boric acid is known to be much more soluble.
U.S. Pat. No. 4,332,609 issued to Ott, which is incorporated by reference in its entirety, discusses the means of producing just such a water-soluble concentrate of boric acid and Monoethanolamine. The disadvantage is that the plants must convert this boric acid Monoethanolamine complex to boric acid in order to use it. Furthermore, boron is often applied in conjunction with a variety of agricultural pesticides that are subject to degradation at high pH ranges. The boric acid Monoethanolamine salt produces high pH solutions and therefore is detrimental to many pesticides.
U.S. Pat. No. 5,877,112 assigned to Helena Chemical Company, which is incorporated by reference in its"" entirety, decribes a composition containing
(a) at least one acid ester surfactant (phosphate ester surfactants)
(b) at least one amine containing surfactant
(c) and at least one water soluble agricultural chemical.
The formulation is expensive, largely because of the addition of phosphate ester surfactants. It would be beneficial if there were alternative, less expensive ways of obtaining formulation stability than using phosphate esters. Furthermore, the phosphate ester surfactants contribute to the eye irritation severity of the overall formulation.
U.S. Pat. No. 5,389,598 assigned to Monsanto Company, which is incorporated by reference in its entirety, describes a storage stable aqueous composition containing
(a) water-soluble pesticide or plant growth modifying agent,
(b) an alkylamine surfactant,
(c) a C6-C22 saturated or unsaturated alkyl monocarboxylic or dicarboxylic acid
(d) and water.
The third ingredient (c) C6-C22 saturated or unsaturated alkyl monocarboxylic or dicarboxylic acid is essential and must be present in a ratio alkoxylated alkylamine surfactant to C6-C22 saturated alkyl mono or dicarboxylic acid from at least about 2:1. The ratio of glyphosate to carboxylic acid is from about 10:1 (a) to about 100:1 and preferably about 10:1 to 40:1. Fattyamine ethoxylates have been known to be used in agricultural formulations in the past. Specifically, tallowamine ethoxylate surfactant is known to enhance glyphosate activity and translocation.
WO 00/41567 describes the use of an adjuvant composition containing
(a) polyoxyalkylene aliphatic amine
(b) an eye irritation reducing compound (carboxylic acid)
(c) mixture of polyhydric alcohols preferably a trihydric alcohol and at least one diol such as ethylene glycol or propylene glycol.
The carboxylic acid is present in an amount from about 0.05 to about 5 wt. % of the adjuvant. When the adjuvant is used with glyphosate, the amount of carboxylic acid in the formulation is from about 0.2 to about 0.4% wt. %.
We have found that the invention can work without a polyhydric alcohol or a mixture of polyhydric alcohols. Furthermore, the invention can be practiced with an eye irritating amount of carboxylic acid which is the opposite taught by WO 00/41567.
The present invention is a composition comprising
(a) a carboxylic acid or phosphorous containing acid providing that the phosphorous containing acid is not a glyphosate,
(b) an amine containing surfactant,
(c) at least one water soluble agricultural chemical with the proviso that the composition contains less than 3 percent by weight of phosphate ester surfactant. It is more preferable, that there is less than about 1 percent by weight of phosphate ester surfactant and most preferable there is no phosphate ester surfactant present. We have found that the invention can work without a polyhydric alcohol or a mixture of polyhydric alcohols. Furthermore, the invention can be practiced with an eye irritation amount of carboxylic acid. The amount of the carboxylic acid used is preferably an eye irritating amount greater which would be greater than 0.4 wt. %. More preferably, the amount of the carboxylic acid is at least 1%, and even more preferably at least 4 wt. % and even more preferably at least 6 wt. % and most preferably at least 7 wt. %.
The present invention is also a homogenous agricultural liquid composition containing at least (a) a carboxylic acid or phosphorus containing acid, (b) an amine containing surfactant, preferably a fatty amine ethoxylate surfactant, (c) and at least one other agricultural chemical without substantially no or no acid ester surfactants such as phosphate ester surfactants.
The agricultural chemical referred to herein, can used in agricultural or non-agricultural applications. The agricultural applications include, but are not limited to pesticide, fertilizer, or plant growth regulators. The non-agricultural applications include, but are not limited to forestry, aquatics, right of way (such as the areas along roads or medians), turf (such as lawns, golf courses etc.) ornamental (such as plants for their beauty) or municipal (parks, school, open land, etc).
The present invention works with substantially no or no phosphate ester surfactant. The preferred embodiment can have a weight/weight ratio of glyphosate to carboxylic acid less than about 10:1 and more preferably less 8:1 and most preferably less than about 7:1. The glyphosate and carboxylic acid are most preferably in a weight/weight ratio of glyphosate to carboxylic acid in a 8:1 to about 2:1.
A further embodiment of the invention is a composition comprising:
(a) a phosphorous containing acid providing that the phosphorous containing acid is not a glyphosate, (b) an amine containing surfactant of the formula: 
where x,y,a,b,c,d,r, and s are independently a number from 0-100, with e proviso that the sum of a+b+c+d+r+s+x+y must be at least 4,
(c) at least one water soluble agricultural chemical with the proviso that the composition contains less than 3 percent by weight o phosphate ester surfactant.
Optionally, other surfactants or formulation aids can be added. The formulation can have a pH of less than about 7. It is also possible to add a buffering agent to further decrease the pH of the composition.
Preferably, if a carboxylic acid is used, the acid is a monocarboxylic acid, a dicarboxylic acid and a tricarboxylic acid. The acid is formic acid, acetic acid, propionic acid, butyric acid, valeric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, citric acid and phosphoric acid, preferably, citric acid. If a phosphorus containing acid is used, preferably it is phosphoric acid or phosphorous acid. Preferably the amine containing surfactant is a fatty amine and most preferably a tallowamine ethoxylate. The composition allows water-soluble salts of agricultural chemicals to remain stable and soluble at lower than normal pH ranges.